Training alongside the UFC heavyweight champion before a big fight is sort of a mixed blessing for Daniel Cormier.

“The good thing is, you just know that you always have someone to train with,” said Cormier (12-0 MMA, 1-0 UFC), who works out in San Jose with UFC heavyweight titleholder Cain Velasquez (12-1 MMA, 10-1 UFC) at American Kickboxing Academy, where Cormier also serves as head wrestling coach.

“I know I won’t ever be on that bike by myself, because Cain will be there,” Cormier said. “I know I never have to worry about having a sparring partner, because Cain’s always going to be there.”

That’s also the bad news. Not only will Velasquez be there every day Cormier sets foot in the gym, but he’ll also be trying to beat up Cormier.

“We spar hard at least once a week,” Cormier said. “And it sucks.”

It’s also an uncommon luxury. Most MMA gyms are lucky to have one top 10 fighter in any weight class. Quality heavyweights are in especially short supply, which is why other champs are often forced to bring in sparring partners on their own dime.

Cormier and Velasquez are lucky in that sense. As both prepare for their bouts at Saturday’s UFC 166 at Houston’s Toyota Center (pay-perview, 10 p.m. ET), it’s a tremendous advantage to have a training partner who is as good as any in the division, and without having to pay extra for his services. Velasquez defends his title in a rubber match against former champ Junior dos Santos (16-2 MMA, 10-1 UFC) in the main event; Cormier takes on Roy Nelson (19-8, 6-4).

It’s just that it might not actually feel like such a treat when that same training partner is thumping on your head in practice each week.

“I know I’ve been in harder fights with (Cormier) than I have in the cage,” Velasquez said. “There isn’t a tougher fight out there for me than him. I’m going against the best guy every day.”

The trouble is, you can only have two top heavyweights under one roof for so long before the pressure to see them fight each other becomes overwhelming.

The pressure has torn apart similar partnerships in other gyms, though Cormier and Velasquez insist it won’t happen to them.

That’s partly because, according to Cormier, the bout with Nelson will be his last at heavyweight. He said he had already begun a gradual slimming down process and win or lose at UFC 166 was relocating to the light heavyweight division.

Is it because Cormier wants to avoid a fight with his training partner? Or is it because the former U.S. Olympic wrestling team captain genuinely likes his chances better at 205 pounds, where he’d likely end up on a crash course with dominant UFC light heavyweight champ Jon Jones?

“I think it’s both,” Cormier said. “I don’t want to fight Cain, obviously, and I want to hold the belt at the same time that my teammate does. I think that would be great for our gym. It’s also that, when I first started this sport, I didn’t want to think about losing weight and worrying about that aspect of the sport, because I just needed to get skills first. I was so raw. I didn’t have the skills where I could aftord to take on another thing to worry about. Now I can.”

So far, the drop in weight has gone according to plan, Cormier said. He has had to cut back on some of his favorite treats — and eliminate others, such as soda and chicken with gravy — but he’s on his way to becoming a light heavyweight.

“I can feel the differences in my body,” Cormier said. “It’s better than I expected it to be.”

If it all pans out the way Cormier plans, it will also help keep his collaborative partnership with Velasquez intact. It might even get fans and members of the news media to stop wondering what would happen if the two met in the cage for something other than a sparring session.

Not that that has been much of a distraction for the fighters, Velasquez said, since “we didn’t really think about it before. We knew we weren’t going to do it no matter what.”

It’s hard to blame them, considering how successful they’ve been together. Cormier is unbeaten since coming to MMA from amateur wrestling, while Velasquez has one loss, a knockout suered in his first meeting with dos Santos, who he faces for a third time after easily winning the second bout by unanimous decision.

“I think we both have tough fights (at UFC 166), but Cain probably has the tougher one,” Cormier said. “It’s a guy who’s beat him before and a guy who’s proven to be one of the best in the world. Anytime you get two guys like that in there, you know it’s going to be a fight.”

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